Check if pointer size reflects architecture
Check if pointer size reflects architecture

Add stronger check to validate if architecture and machine are
equivalent. Error out to inform user to invoke `make menuconfig`.

Avoids compiling for the wrong architecture (e.g. docker images).

Fixes #8.

klee/klee-uclibc,klee/klee-uclibc,klee/klee-uclibc,klee/klee-uclibc